Land of unicorns

Whenever you play a spell, you may pay {0},
if you do, put X unicorn counters on Land
of unicorns, where X is the number of
different color symbols in the mana cost of
the spell. You can only pay once per turn.
{t}: add {c}.
{t}, remove five unicorn counters from Land
of unicorns: add {w}{u}{b}{r}{g}.